/**
 * Event types for database operations
 */
export declare enum DatabaseEventType {
    WRITE_OPERATION = "write_operation",
    READ_OPERATION = "read_operation",
    TRANSACTION_COMPLETE = "transaction_complete",
    ERROR = "error"
}
/**
 * Database event system to facilitate communication between services
 * Uses the publish-subscribe pattern to decouple components
 */
declare class DatabaseEventSystem {
    private emitter;
    private static instance;
    private constructor();
    /**
     * Get the singleton instance
     */
    static getInstance(): DatabaseEventSystem;
    /**
     * Subscribe to a database event
     * @param eventType Event type to subscribe to
     * @param listener Function to call when the event occurs
     */
    subscribe<T>(eventType: DatabaseEventType, listener: (data: T) => void): void;
    /**
     * Unsubscribe from a database event
     * @param eventType Event type to unsubscribe from
     * @param listener Function to remove
     */
    unsubscribe<T>(eventType: DatabaseEventType, listener: (data: T) => void): void;
    /**
     * Publish a database event
     * @param eventType Event type to publish
     * @param data Event data
     */
    publish<T>(eventType: DatabaseEventType, data: T): void;
    /**
     * Subscribe to a database event only once
     * @param eventType Event type to subscribe to
     * @param listener Function to call when the event occurs
     */
    subscribeOnce<T>(eventType: DatabaseEventType, listener: (data: T) => void): void;
}
export declare const databaseEvents: DatabaseEventSystem;
export {};